Police divers are combing through underwater areas of New York’s Central Park in the hunt for evidence about the killer of a healthcare boss.
Detectives searching for the man believed to have targeted UnitedHealthcare CEO Brian Thompson have found a backpack and have multiple images of the suspect.
But, so far, they have not found the weapon used when Mr Thompson arrived at the Hilton hotel for his company’s annual investor conference at 6.44am on Wednesday.
Two sources have told Sky News’ US sister channel NBC News that the New York Police Department’s scuba team has now joined the investigation.
The sources said they are specifically trained to recover evidence while diving, using specific techniques and equipment.
Since the waters are likely murky, the source said, the divers will make an underwater grid pattern to search for evidence. They are also knowledgeable on how to preserve evidence if found underwater.
It is understood there is a pond in Central Park close to the escape route used by the killer after the shooting. Pictures in some US media show divers searching around the boating lake in the famous New York park.
The investigators believe the killer used a 9mm pistol that resembled a gun that farmers use to put down animals without causing a loud noise.
They also know ammunition found near Thompson’s body had been inscribed with the words “delay,” “deny” and “depose”, mimicking a phrase used by insurance industry critics.
Among the theories being worked on are that the gunman knew UnitedHealthcare group was holding a conference at the hotel and the route Thompson took to get there, so he could possibly be a disgruntled employee or client, NYPD chief of detectives Joseph Kenny said.
Brian Thompson shooting suspect Pic: NYPD
On Sunday afternoon, while they did release new images, police declined to comment on the contents of the backpack, or on the results of the search in the pond.
But the day before, sources told NBC News police found money from a Monopoly game inside the backpack they believe the gunman used.
Hundreds of detectives are pouring over video recordings and social media posts, checking tips from the public and carrying out interviews.
A map showing some of the key locations in the Brian Thompson killing
Among those being questioned are Thompson’s family and co-workers and the gunman’s randomly assigned roommates at the Manhattan hostel where he stayed.
Police believe the killer likely took a bus out of New York soon after the brazen ambush.
Before he arrived in New York, he travelled from Atlanta.
Detectives are searching for video from that bus station and others along the Greyhound Bus route.
Other video found by detectives shows the man riding a bicycle into the park and later taking a taxi to a bus station from where he could travel to New Jersey, Philadelphia, Boston and Washington DC, according to Mr Kenny.